218 



Rhenoeter Bush, 56, 57, 68, 96, 97, 102, 105, 139. 



,, ,, an indication of poor soil, 56, 68, 96, 102. 



Richmond Division, 20, 21, 110, 155. 

 Rio Grande silt, 109, 203. 



River deposits, fertility of (see also Silts), 53, 60, 66, 70, 91, 98, 108, 113. 

 improvement of sandy soils by, 203. 



,, retaining weirs for, 91, 109. 



Riversdale Division, 4, 19, 21, 29, 90, 109, 111-114, 129, 154. 

 Robben Island, 41, 42. 

 Robertson Division, 4, 19, 20, 22, 32, 115-120, 129, 132, 133, 147, 155, 184. 



Experiment Station, 115, 153, 156, 184, 199-201. 



results of mechanical soil analyses, 200, 201. 



Roode Zand Mountains, 135. 

 Root action, increase of, results in depletion of reserve plant food, 12. 



variable in different plants, 3. 

 Roots, Acid excretions from, 2. 

 Rothamsted Experimental Farm, 11, 17. 

 Ruggens, The, 29, 112, 113, 116, 130. 



types of Bokkeveld soil, 29, 30, 112. 

 Rumex acetosella, 40. 

 Russian agronomic surveys, 11. 

 Rust in cereal crops, 40, 81, 104, 149. 

 Rust-proof localities, 81, 82, 83, 102. 



St. Helena Bay, 79, 84. 



St. John's River, 107, 171. 



St. Mark's District, 19, 21, 121. 



Saldanha Bay, 79, 87. 



Salisbury, Taungs District, 26. 



Salsola aphylla : see " Ganna." 



Salt bush, 26, 83. 



Salts, Proportions of, in soil compatible with growth of crops, 174, 175. 



Sand downs : see Blown sands. 



Sandstone, Influence of, upon chemical composition of soil, 139, 159, 161, 163. 



Sandstone soils, Poverty of, 24, 36, 38, 39, 42, 51, 53, 57, 59, 64, 75, 92, 93, 97, 99, 



100, 134, 135, 139, 148, 150, 152, 159, 163, 164, 168. 

 Sandy soils, Physical composition of, 189. 

 Saussure, H. E. de, 1. 

 Scheme of mechanical soil analysis, 195. 

 Schryvers Hoek, F.C., 79, 87. 

 Schiibler, J. J., 11, 189. 

 Sea Point, 41. 



Sedimentation in mechanical soil analysis, 1, 191, 194. 

 Sieves for mechanical soil analysis, 3, 7, 193. 

 Sifting of soil, 1, 3, 13, 154, 193. 

 Silicates and plant food, 9. 

 Silt, application of the term, 190, 191, 195. 



importance of, in mechanical soil analysis, 191. 

 Silts, 24, 91, 108, 113, 170, 171, 191. 



and clays richer than coarse grained soils, 13, 24, 53, 191. 

 ,, deposited by rivers, analyses of, 171. 

 Simondium, 104. 



Situation, unfavourable, effect on productiveness, 18. 

 Slates, Malmesbury : see Malmesbury series. 

 Snyder, Prof. H., 11, 190, 192. 



Sodium sulphate and carbonate in alkaline soils, 173. 

 Soil analysis, Prejudice against, 11. 

 constituents, determination of *7. 



chlorine, 7, 8. 



lime, 7, 13, 15, 16. 



moisture, 7. 



nitrogen, 7, 8. 



organic matter, 7. 



phosphoric oxide, 7, 14, 15, 16, 17. 



potash, 7, 8, 14, 16. 



chemical analysis of 



its value, 2, 5, 8, 11. 



olutriation of, 1. 



exhaustion, 45. 



extraction by boiling hydrochloric acid, 126, 155. 



